Transmission apparatus and reception apparatus

ABSTRACT

A transmission apparatus used in a mobile communication system adopting a single carrier scheme in an uplink includes: multiplexing means configured to multiplex a pilot channel, a control channel, and a data channel; and transmission means configured to transmit a transmission symbol including at least the pilot channel and the control channel using the uplink. A first pilot channel used for a reception apparatus to measure channel state of the uplink is transmitted using a frequency band over a plurality of resource blocks. A second pilot channel for compensating for a channel transmitted by the uplink is transmitted by a resource block assigned to the transmission apparatus. Control channels of the transmission apparatus and the apparatus other than the transmission apparatus are orthogonalized with each other by a FDM scheme.

TECHNICAL FIELD

The present invention relates to a technical field of radiocommunications. More particularly, the present invention relates to atransmission apparatus and a reception apparatus used in a downlink.

BACKGROUND ART

In a next generation radio access scheme for which research anddevelopment are currently being conducted, it is required to performcommunication more efficiently compared with conventional schemes. Inthe downlink, speed-up and increase of capacity for communication areespecially required. Thus, radio access schemes of a multicarrier schemesuch as orthogonal frequency division multiplexing (OFDM) are highlyexpected. On the other hand, the uplink is different from the downlinkin that speed-up and large capacity are not so strongly required for theuplink as the downlink and that transmission power of a mobile stationis considerably limited compared with that of the base station and thelike. Thus, the multicarrier scheme in which there is a fear that peakto average power ratio (PAPR) becomes large is not a proper scheme forthe uplink. Rather, from the viewpoint of suppressing PAPR andincreasing coverage of a cell, it is desirable to adopt a single carrierscheme for the uplink.

By the way, there are data channels, control channels and pilot channelsand the like as channels to be transmitted on the uplink, and thechannels include various types of channels having different functions.For example, as to the pilot channels, in addition to a pilot channelfor channel compensation for assigned radio resources, there is a pilotchannel for channel compensation for unassigned radio resources. Inaddition, the control channel may include information such astransmission confirmation information (ACK/NACK) of a previouslyreceived downlink data channel and the like in addition to information(for example, information indicating a modulation scheme and a channelcoding rate and the like) used for demodulating an uplink data channel.For example, the patent document 1 describes types and properties of theuplink channels.

[Non-patent document 1]3GPP, TR25.814, “Physical Layer Aspects forEvolved UTRA”

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

However, a proper uplink frame considering properties of theabove-mentioned various uplink channels has not yet been established. Inaddition, in the next generation radio access scheme, wide range ofsystem frequency bands are prepared and it is assumed that mobilestations perform communications using the whole or a part of the bands.However, an uplink frame suitable for use in various wide and narrowbands has not yet been established.

The present invention is contrived for addressing at least one of theproblems, and the object is to provide a transmission apparatus and areception apparatus for realizing a proper uplink frame for transmittingvarious uplink channels.

Means for Solving the Problem

In the present invention, a transmission apparatus used in a mobilecommunication system adopting a single carrier scheme in an uplink isused. The transmission apparatus includes: multiplexing means configuredto multiplex a pilot channel, a control channel, and a data channel; andtransmission means configured to transmit a transmission symbolincluding at least the pilot channel and the control channel using theuplink. The pilot channel includes a first pilot channel used for areception apparatus to measure channel state of the uplink and a secondpilot channel for compensating for a channel transmitted by the uplink.The data channel is transmitted using one or more resource blocks. Thefirst pilot channel is transmitted using a frequency band over aplurality of resource blocks. The second pilot channel is transmitted bya resource block assigned to the transmission apparatus. Controlchannels of the transmission apparatus and the apparatus other than thetransmission apparatus are orthogonalized with each other by a frequencydivision multiplexing (FDM) scheme.

EFFECT OF THE INVENTION

According to the present invention, a proper uplink frame fortransmitting various uplink channels can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of a transmitter according to anembodiment of the present invention;

FIG. 2 is a schematic block diagram of a receiver according to anembodiment of the present invention;

FIG. 3 shows a detailed diagram of the shared control channel generationunit;

FIG. 4 is a diagram showing an example of bands used in a system;

FIG. 5A is a diagram showing a manner in which information of a user Aand information of a user B are multiplexed by the distributed FDM;

FIG. 5B is a diagram showing a manner in which information of a user Aand information of a user B are multiplexed by CDM and the distributedFDM;

FIG. 5C is a diagram showing a manner in which information of a user Aand information of a user B are multiplexed by the localized FDM;

FIG. 6A is a diagram showing a mapping example of a pilot channel, acontrol channel, and a data channel;

FIG. 6B is a diagram showing a mapping example of a pilot channel, acontrol channel, and a data channel;

FIG. 7 is a diagram showing a mapping example of a pilot channel, acontrol channel, and a data channel;

FIG. 8 is a diagram showing a mapping example of a pilot channel, acontrol channel, and a data channel; and

FIG. 9 is a diagram showing a mapping example of a pilot channel, acontrol channel, and a data channel.

DESCRIPTION OF REFERENCE SIGNS

-   231 pilot channel generation unit-   233 shared control channel generation unit-   235 shared data channel generation unit-   236, 241 discrete Fourier transform unit-   237, 242 mapping unit-   238, 243 inverse fast Fourier transform unit-   244 demultiplexing unit-   251-253 switch-   255-258 modulation and coding unit-   259 multiplexing unit

PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION

According to an embodiment of the present invention, a first pilotchannel used for a reception apparatus to measure channel state of theuplink is transmitted by a wide band, and a second pilot channel forcompensating for a channel transmitted by the uplink is transmitted by aresource block assigned to the user apparatus. Thus, quality measurementfor each resource block can be properly performed, and channelcompensation and the like for assigned resource blocks can be alsoproperly performed.

In addition to obtaining frequency diversity effect, in view ofobtaining orthogonality easily and with reliability, control channels ofthe transmission apparatus and the apparatus other than the transmissionapparatus may orthogonalized with each other by a distributed FDMscheme.

From the viewpoint of transmitting a control channel by a resource blockin a good channel state, it is desirable that the control channel of thetransmission apparatus is also transmitted in a resource block assignedfor data channel of the transmission apparatus.

From the viewpoint of especially expecting frequency diversity effect,the control channel of the transmission apparatus may be transmittedusing not only the resource block for the data channel but also a wideband equal to or greater than the resource block assigned for the datachannel of the transmission apparatus.

From the viewpoint of improving throughput considering superiority andinferiority of channel state of each user, the control channel of thetransmission apparatus may be transmitted using a frequency band of oneor several number of resource blocks.

Data channels of the transmission apparatus and the apparatus other thanthe transmission apparatus may be orthogonalized with each other by theFDM scheme, and pilot channels of the transmission apparatus and theapparatus other than the transmission apparatus may be orthogonalizedwith each other by the CDM scheme.

Embodiment 1

Before describing the apparatus configuration and the operationaccording to an embodiment of the present invention, it can beconsidered meaningful to explain the outline of various types ofchannels transmitted on the uplink. Uplink channels are broadly dividedinto (A) Contention-based channels, (B) Contention non-permittedchannels and (C) Pilot channels. The contention-based channel is achannel for which scheduling is not required in a base station beforetransmission, and the contention non-permitted channel is a channel(scheduled channel) for which scheduling is required in a base stationbefore transmission. The contention-based channel includes one or moreof (A1) High speed access channel, (A2) Reservation channel and (A3)Uplink synchronization channel. The contention non-permitted channelincludes one or more of (B1) uplink shared data channel and (B2) uplinkshared control channel.

(A) [Contention-Based Channel]

The contention-based channel to be transmitted from the mobile stationwithout scheduling in the base station can be transmitted at any time bya mobile station (more generally, user apparatus (UE: user equipment)that includes a fixed station). It is desirable that thecontention-based channel is transmitted over a wide band. By doing that,transmission time can be decreased. In addition, since the band is wide,frequency diversity effect can be obtained. Thus, even though signalquality deteriorates very much in a part of frequencies, poweramplification (power ramping) and the like for compensating for thedeterioration is not essential. Although contention may occur betweenusers for the contention-based channel, high speed communication isavailable easily by the channel. Although time division multiplexingscheme (TDM) is used in the same way as the current UTRA, frequencydivision multiplexing and/or code division multiplexing (CDM) isperformed in the present embodiment from the viewpoint of reducingcontention with other users as much as possible. However, whencontention against other user occurs, these users may transmit thecontention-based channel again as necessary.

(A1) Fast Access Channel

The fast access channel may include a control message of a small datasize, may include traffic data of a small data size, or may include bothof them. One reason for limiting the data size to be small is forreducing transmission delay. For example, the control message mayinclude information on layer 3 handover, for example. The traffic dataof the small size may include an e-mail of a small information amount, acommand of a game and the like. Since the user apparatus can transmitthe fast access channel to the base station without any priorreservation, process time required for transmission can be small. Thefast access channel is transmitted by one or more frequency chunksassigned beforehand. Which chunk is to be used in a plurality offrequency chunks may be reported from the base station to the userapparatus by a broadcast channel of a downlink. The content of thereport may indicate that only a particular frequency chunk can be usedor may indicate any one (or any number) of a plurality of particularfrequency chunks can be used. The latter one is advantageous in thatprobability for contention between users is less than that of the formerone.

(A2) Reservation Channel

The reservation channel includes information for requesting schedulingof a contention non-permitted channel. The information may includeidentification information for identifying a user apparatus, trafficdata type (voice, image, and the like), data size, required qualityinformation (QoS and the like), and transmission power of the userapparatus and the like. The reservation channel is also transmitted by afrequency chunk assigned beforehand. Which chunk is to be used in aplurality of frequency chunks may be reported from the base station tothe user apparatus by a broadcast channel of a downlink.

(A3) Uplink Synchronization Channel

In the present embodiment, signal transmission of an uplink is performedusing a single carrier scheme, and equalization is performed forsuppressing multipath interference. For performing effectiveequalization, it is desirable to maintain synchronization such thatreception timing for reception from various users fall within a periodof a predetermined guard interval. For maintaining the synchronization,uplink synchronization channel is used.

By the way, maintaining synchronization can be also realized by theafter-mentioned pilot cannel. Therefore, it is not essential to prepareboth of the synchronization channel and the pilot channel.

(B) [Contention Non-Permitted Channel]

The contention non-permitted channel is transmitted from the userapparatus according to scheduling performed in the base station.

(B1) Uplink Shared Data Channel

The uplink shared data channel includes both or one of traffic data anda control message of layer 3. The control message may includeinformation on handover, information necessary for retransmissioncontrol and the like. The uplink shared data channel is assigned one ormore resource blocks (or chunks) according to scheduling in time domainor both of time and frequency domains. In this case, resource assignmentis scheduled in the base station such that a user related to a bettertransmission route (channel) in the time domain or in both of the timeand frequency domains can transmit packet in priority. The number ofresource blocks to be assigned is determined depending on a data rateand a data size and the like to be transmitted by the user apparatus.When there are a plurality of users requesting only a relatively lowdata rate, one resource block may be shared by a plurality of users.However, when a traffic size of a user exceeds a predetermined size, oneuser may use the whole of the resource block. In addition, one user mayuse a plurality of resource blocks. When one resource block is shared bya plurality of users, multiplexing in some manner is performed such thatchannels of a plurality of users become orthogonal in the resourceblock. For example, localized FDM or distributed FDM may be performed inthe resource block.

(B2) Uplink Shared Control Channel

Uplink shared control channel transmits a physical control message and alayer 2 control message (FFS). As to the uplink shared data channel,resource assignment is scheduled in the base station such that a userrelated to a better transmission route (channel) can transmit a packetin priority. However, as to the uplink shared control channel,scheduling depending on superiority or inferiority of channel state isnot essential (however, some link adaptation may be performed for theshared control channel). The base station assigns resource blocks toeach user apparatus to perform scheduling to avoid contention of sharedcontrol channels. As to the uplink shared control channel, the basestation performs scheduling depending on the number of users. In orderto maintain packet error rate to be low, it is desirable to performtransmission power control with high precision. In addition, it isdesirable to obtain frequency diversity effect by transmitting theuplink shared control channel over a wide range of frequencies so as toincrease quality of reception packets.

More particularly, the uplink shared control channel includes one ormore of:

(1) control information related to a scheduled uplink shared datachannel;

(2) control information related to a scheduled downlink shared datachannel;

(3) control information for changing content of scheduling of the uplinkshared data channel; and

(4) control information for performing scheduling of a downlink shareddata channel.

In these types of control information, (1) includes control informationessential for demodulating the uplink shared data channel, and isessential control information that should associated with the uplinkshared data channel. On the other hand, as to (2) and (4), it is notessential that they are associated with the uplink shared data channel,and they are control information (control information different from theessential control information) that are not necessarily associated withthe uplink shared data channel. According to such classification method,the control information (3) related to change of scheduling content maybe included in the essential control information, or may be included incontrol information different from the essential control information.

(1) The control information (essential control information) related toscheduled uplink shared data channel is transmitted being associatedwith an uplink shared data channel only when the uplink shared datachannel is transmitted. This control information is also called anassociated control channel, and may include information necessary fordemodulating shared data channel (modulation scheme, channel coding rateand the like), transmission block size, information related toretransmission control, and the like, and may be represented withinformation amount of about 14 bits, for example. For example, theretransmission control information may include information indicatingwhether a packet transmitted by the uplink shared data channel is aretransmission packet or a new packet, information indicating use methodof the retransmission packet, and the like. For example, data of theretransmission packet is the same as data of a previously transmittedpacket (initial transmission data, for example) in a first use method,and data of the retransmission packet may be different from data of apreviously transmitted packet in a second use method. In the lattercase, packet combining can be performed with redundancy information oferror correcting coding.

(2) The control information associated with the scheduled downlinkshared data channel is transmitted to the base station only when adownlink shared data channel is transmitted from the base station andthe downlink shared data channel is received by the user apparatus. Thiscontrol information represents transmission confirmation information,that is, whether the packet is properly received on the downlink(ACK/NACK), and it can be represented by 1 bit in a simplest case.

(3) The control information for changing content of scheduling of theuplink shared data channel is transmitted for reporting a buffer sizeand/or transmission power of the user apparatus to the base station.This control information may be transmitted periodically or irregularly.For example, it mat be transmitted from the user apparatus at a timewhen the buffer size and/or the transmission power change. The basestation may change the scheduling content according to such a statuschange of the user apparatus. The status of the buffer size and thetransmission power may be represented using an information amount ofabout 10 bits, for example.

(4) Control information for performing scheduling for the downlinkshared data channel is transmitted for reporting channel qualityinformation (CQI: channel quality indicator) of the downlink to the basestation. The CQI may be reception SIR measured by the user apparatus,for example. This information may be transmitted periodically orirregularly. For example, this information may be reported to the basestation when the channel quality changes. This control information maybe represented using an information amount of 5 bits, for example.

(C) [Pilot Channel]

The pilot channel is a signal having a pattern that is known beforehandin the transmission side and in the reception side, and it can also bereferred to as a reference signal, a known signal, a training signal andthe like.

The pilot channel can be transmitted from the user apparatus using thetime division multiplexing (TDM), the frequency division multiplexing(FDM), code division multiplexing (CDM), or a combination of these.However, from the viewpoint of decreasing peak-to-average power ratio(PAPR), it is desirable to use a TDM scheme. By orthogonalizing a pilotchannel and a data channel using the TDM scheme, the pilot channel canbe correctly separated in the reception side, so that it contributes toimprovement of channel estimation accuracy.

The pilot channel includes a first pilot channel for CQI measurement forevery resource block that has a chance to be assigned to the userapparatus in the future, and includes a second pilot channel for channelcompensation of a channel transmitted by a resource block that iscurrently assigned to the user apparatus. As mentioned later, the firstpilot channel is transmitted by a wide band including all resourceblocks and the second pilot channel is transmitted only by a particularresource block assigned to the user apparatus.

FIG. 1 is a schematic block diagram of a transmitter according to anembodiment of the present invention. The transmitter shown in the figureis typically provided in a user apparatus. FIG. 1 shows a pilot channelgeneration unit 231, a shared control channel generation unit 233, ashared data channel generation unit 234, a multiplexing unit 235, adiscrete Fourier transform unit (DFT) 236, a mapping unit 237 and aninverse fast Fourier transform unit 238.

The pilot channel generation unit 231 generates a pilot channel used inthe uplink. The pilot channel includes the above-mentioned first and thesecond pilot channels at least.

The shared control channel generation unit 233 generates a sharedcontrol channel that may include various control information. The sharedcontrol channel generation unit 233 is described with reference to FIG.3 later.

The shared data channel generation unit 234 generates a shared datachannel transmitted by the uplink.

The multiplexing unit 235 multiplexes and outputs one or more channels.It is not essential to multiplex all of the channels shown in thefigure, and one or more channels are multiplexed as necessary. In theexample shown in the figure, processing of time division multiplexing isperformed by the multiplexing unit 235, and processing of assuagement tofrequency components is performed by the mapping unit 237. Sincescheduling for the time division multiplexed signal is performed basedon an instruction by the base station, the signal is classified to thecontention non-permitted channel.

Actually, a contention-based channel is also generated and ismultiplexed and transmitted as necessary. But, for the sake ofsimplicity of explanation, this is not shown.

The discrete Fourier transform unit (DFT) 236 performs Fourier transformon a signal (signal after being multiplexed in the example shown in thefigure) input to the unit. In this stage of the signal processing, sincethe signal is discrete digital values, discrete Fourier transform isperformed. By doing that, a sequence of signals arranged in order oftime is represented in the frequency domain.

The mapping unit 237 maps each signal component after Fourier transformto a predetermined subcarrier on the frequency domain. The frequencydivision multiplexing (FDM) scheme in this case may be a localized FDMscheme for assigning one continuous narrow band to one user or may be adistributed FDMA scheme for giving a spectrum in which a plurality offrequency components are arranged by being distributed at predeterminedfrequency intervals. The predetermined frequency intervals are regularintervals generally, but the predetermined frequency intervals may beirregular intervals. The mapping unit 237 performs mapping on thefrequency axis by the localized FDM or by the distributed FDM.

The inverse fast Fourier transform unit 238 performs inverse fastFourier transform on the signal components after mapping so as to outputa sequence of signals arranged in order of time.

By the way, the distributed FDM may be realized by Variable Spreadingand Chip Repetition Factors-CDM (VSCRF-CDM) scheme and the like.

FIG. 2 shows a schematic block diagram of a receiver according to anembodiment of the present invention. The receiver shown in the figure isprovided in a base station typically. FIG. 2 shows a discrete Fouriertransform unit (DFT) 241, a mapping unit 242, an inverse fast Fouriertransform unit 243 and a multiplexing unit 244.

The discrete Fourier transform unit (DFT) 241 performs Fourier transformon a signal (reception signal in the example shown in the figure) inputto the unit. Accordingly, a sequence of signals arranged in order oftime can be represented in the frequency domain.

The mapping unit 242 extracts predetermined subcarrier components fromsignals after Fourier transform. Accordingly, signals that aremultiplexed by the localized FDM or the distributed FDM are separated,for example.

The inverse fast Fourier transform unit 242 performs inverse fastFourier transform on signal components after being separated to output asequence of signals arranged in order of time.

The demultiplexing unit 244 separates one or more channels to outputthem. In the example shown in the figure, signals mapped to thefrequency components are restored to signals before mapping by thedemapping unit 242, and the separation of the time multiplexed signal isperformed by the demultiplexing unit 244.

One or more channels generated in the generation unit of each channelare time-multiplexed (properly switched) by the multiplexing unit 235,and the multiplexed signal is input to the DFT 236 so that the signal istransformed to a signal in the frequency domain. The signal aftertransform is properly mapped to the frequency component by the mappingunit 237, and input to the IFFT 238 so as to be converted to time seriessignals. After that, the signal is transmitted by radio via processelements such as the RF unit 14 shown in FIG. 1. This signal is receivedby the receiver shown in FIG. 2. The reception signal is input to theDFT 241, and is transformed into a signal in the frequency domain. Thetransformed signal is a signal mapped to the frequency component, andseparated by the demapping unit 242 to a signal before mapping. Theseparated signal is transformed to time series signals, and thetime-multiplexed signal sequence is properly demultiplexed by thedemultiplexing unit 244, and further demodulation process and the likeis performed by process elements not shown in the figure.

FIG. 3 shows a detailed diagram of the shared control channel generationunit 233. FIG. 3 shows switches 251, 252 and 253, modulation and codingunits 255, 256, 257 and 258, and a multiplexing unit 259. Each switchprovides each channel that is input to one end (left side of the figure)to another end according to an instruction signal (not shown in thefigure) on the shared control channel. The content of the instructionsignal determines how to configure the shared control channel, that is,which control information is included in the shared control channel. Inthe example shown in the figure, the figure shows (1) essential controlinformation, (2) transmission confirmation information of downlinkchannel (information indicating acknowledgement (ACK) and negativeacknowledgement (NACK)), (3) information for changing content ofscheduling and (4) channel state information (CQI) indicating receptionquality of downlink pilot channel.

Each of the modulation and coding unit performs data modulation on achannel input to the unit using an instructed modulation scheme, andperforms channel coding using an instructed coding scheme. Themodulation scheme and the coding scheme used for each channel may bedifferent or same schemes may be used for more than one channel. Themodulation scheme or the coding scheme may be fixedly set so as to beunchanged.

The multiplexing unit 259 multiplexes each channel to generate andoutput the shared control channel.

In transmission of the shared control channel in the conventionaltechnique, the modulation scheme and the coding scheme are fixed, and itis intended to obtain required quality by controlling transmission powercontrol. However, in view of increasing quality of channel and effectiveuse of resources, it is desirable to perform further link adaptation ontransmission of the shared control channel. As a method for performinglink adaptation, there are adaptive modulation and coding (AMC), andtransmission power control (TPC).

FIG. 4 shows frequency bands used in the communication system. Thefrequency band provided to the system (to be also referred to as wholefrequency band or system band) includes a plurality of system frequencyblocks, so that the user apparatus can perform communication using oneor more of resource blocks included in the system frequency blocks. Theresource block is also called a chunk or a frequency chunk. In general,one chunk may include one or more carries (to be also referred to as asubcarrier). But, in an embodiment of the present invention, a singlecarrier scheme is adopted so that one chunk includes only one carrier.

In the example shown in FIG. 4, the system band is 10 MHz, the systemfrequency block is 5 MHz, and the system band includes two systemfrequency blocks. For the sake of simplicity of drawing, the systemfrequency band 2 is not shown. The resource block is 1.25 MHz, and onesystem frequency block includes four resource blocks. Which can be usedin the two system frequency blocks by the user apparatus is determinedby the base station based on a bandwidth by which the user apparatus canperform communication and a number of users performing communication inthe system. The bandwidth of the system frequency block is designed as aband by which every user apparatus that may perform communication in thesystem can perform communication. In other words, the bandwidth of thesystem frequency block is determined as a maximum transmission bandwidthof a user apparatus of a minimum grade that can be assumed. Therefore, auser apparatus that can only perform communication using the band of 5MHz is assigned only one of the system frequency blocks, but, a userapparatus that can perform communication using a band of 10 MHz may beassigned a band such that the user apparatus can use both of the systemfrequency blocks. In the present embodiment, although a subframe may becalled a transmission time interval (TTI) such as 0.5 ms, for example,any proper interval may be used. These value examples are merely anexample, and any proper values may be used.

The user apparatus transmits an uplink pilot channel to the basestation. The base station determines (performs scheduling) one or moreresource blocks to be used for the user apparatus to transmit the shareddata channel based on the reception quality of the uplink pilot channel.The content of the scheduling (scheduling information) is reported tothe user apparatus using an downlink shared control channel or otherchannel. The user apparatus transmits an uplink shared data channelusing an assigned resource block. In this case, the shared controlchannel (shared control channel including essential control information)associated with the uplink shared data channel is transmitted using thesame resource block. As mentioned above, the uplink shared controlchannel may include control information other than the essential controlinformation.

Resource blocks assigned to a user may change as time advances. Theresource blocks assigned to the user may comply with a frequency hoppingpattern. The content of the hopping pattern may be known before start ofcommunication between the base station and the user apparatus, and maybe reported to the user apparatus from the base station as necessary.From the viewpoint for maintaining average signal quality of the uplinkchannel, it is desirable to use not only a particular resource block butalso various resource blocks.

FIGS. 5A-5C show detailed concrete examples how information of a user Aand a user B are multiplexed in a subframe. In the example shown in FIG.5A, pilot channels and data channels are time-multiplexed. Informationof the user A and the user B are multiplexed using the distributed FDM.In the example of FIG. 5B, pilot channels and data channels aretime-multiplexed and the data channels of the user A and the user B aremultiplexed using the distributed FDM similarly to FIG. 5A, but thepilot channels of the user A and the user B are multiplexed by CDM. Inthe example of FIG. 5C, pilot channels and the data channels aretime-multiplexed, and the data channels of the user A and the user B aremultiplexed by the localized FDM.

FIG. 6A shows a mapping example of information of each user according toan embodiment of the present invention. Although the range shown in thefigure is the whole frequency band and one subframe, the range in thefrequency axis direction may be within a range of one system frequencyblock. For the sake of description, a period in a subframe is dividedinto first-fourth time slots in order of elapse of time. In the firsttime slot, first pilot channels from all users are multiplexed andtransmitted. The all users include all of users that may transmit somechannels in the future in addition to users transmitting the uplink datachannel and users transmitting the uplink control channel. As mentionedabove, the first pilot channel is a pilot channel for measuring CQI forall resource blocks having a chance to be assigned to the user apparatusin the future. Multiplexing of the first pilot channels for all usersmay be performed by FDM, CDM or both of them.

Control channels are mapped to the second time slot. Control channels ofeach user are orthogonalized with each other by the distributed FDM. Asmentioned above, as information included in the shared control channel,there are essential control information essential for demodulating theshared data channel and control information (control information otherthan the essential control information) other than that. In the exampleshown in the figure, users B, C and D transmit control channelsincluding control information other than essential control information.Like the first pilot channel, the users B, C and D distribute thecontrol channels over the whole frequency band (or the whole of thesystem frequency block) to transmit them to the base station. It isassumed that the users B, C and D do not transmit a data channel in anyresource block in this subframe. The user A is assigned one resourceblock, and the user A transmits a data channel in the third time slotusing the resource block. A control channel (including essential controlinformation and control information other than that) of the user A istransmitted using frequencies in the resource block assigned to the userA. The control channel of the user A and control channels of other usersare orthogonalized with each other using the distributed FDM.

In the fourth time slot, the second pilot channel is mapped. Asmentioned above, the second pilot channel is a pilot channel for channelcompensation for a channel to be transmitted by a resource block that iscurrently assigned to the user apparatus. Also in this fourth time slot,first pilot channels transmitted over wide band for CQI measurement maybe multiplexed and transmitted by a plurality of users. Also in thiscase, it is possible to perform channel compensation for a channeltransmitted using the resource block currently assigned to the userapparatus by using a part of the first pilot channel transmitted overthe wide band.

By the way, for the sake of simplicity of the drawing, although any datachannel of users other than the user A is not shown, data channels andthe like of some sort of users (other than the users B, C and D) aremapped to resource blocks other than the resource block assigned to theuser A in actuality.

As to an uplink channel received from the user A, the base stationestimates the channel state of the resource block based on the secondpilot channel, and determines compensation content (phase rotationamount and power and the like) to be performed on the control channeland the data channel so as to perform the compensation. In addition, itis determined which resource block becomes high quality for the user Ain later subframes based on the first pilot channel. The base stationperforms retransmission control and the like based on uplink channels(control information other than the essential control information)received from the users B, C and D. In addition, when resourceassignment request of an uplink has been received, the base stationdetermines which resource block becomes high quality for the user B, Cor D based on the received first pilot channel.

From the viewpoint that the base station determines superiority orinferiority of the channel state of each user for each resource block,it is desirable that the first pilot channel is transmitted using a wideband. From the viewpoint of maintaining minimum reception quality in thebase station by increasing frequency diversity effect, it is desirablethat control channels of the users B, C and D for which any particularresource block is not assigned are distributed to a wide band like theexample shown in the figure. From the viewpoint of transmitting acontrol channel in a good channel state as much as possible, it isdesirable that the control channel of the user A to which a particularresource block is assigned is transmitted by the assigned resource blockas the example shown in the figure. In this case, the second pilotchannel transmitted by the assigned resource block can be also used fordemodulation of the control channel of the user A.

FIG. 6B shows a mapping example of information of each user according toan embodiment of the present invention. Expedient time slots are dividedto five that are first to fifth slots. The firs, second, fourth andfifth time slots are the same as the first to fourth time slots of FIG.6A. However, in FIG. 6B, a control channel that includes controlinformation other than the essential control information of user A istransmitted in the third time slot (before the data channel of the userA is transmitted). In the example shown in the figure, in controlchannels of the user A, the essential control information is transmittedby the second time slot, and control information other than theessential control information is transmitted by the third time slot.Such a scheme is advantageous when information amount of controlinformation other than the essential control information is large (forexample, when control information other than the essential controlinformation is large to a degree in which it is difficult to transmitusing the scheme shown in FIG. 6A).

FIG. 7 shows a mapping example of information of each user according toan embodiment of the present invention. Generally, although this exampleis similar to the example shown in FIG. 6A, this example is deferent inthat each of the control channels (including only control informationother than essential control information) transmitted by the users B, Cand D falls within a range of a resource block instead of beingdistributed over the whole frequency band. When a channel state on aparticular resource block is relatively good, it is desirable that thecontrol channel is transmitted by a particular resource block as shownin FIG. 7.

FIG. 8 shows a mapping example of information of each user according toan embodiment of the present invention. Generally, although this exampleis similar to the example shown in FIG. 6A, this example is deferent inthat not only the control channels (including only control informationother than essential control information) transmitted by the users B, Cand D but also the control channel of the user A are distributed overthe whole frequency band.

FIG. 9 shows a mapping example of information of each user according toan embodiment of the present invention. Although only the data channelof user A is shown in the mapping examples of FIGS. 6A-8, data channelsof other users are shown in FIG. 9. FIG. 9 shows a mapping example fortwo subframes. As shown in the figure, mapping methods may changevariously as time advances.

The present international application claims priority based on Japanesepatent application No. 2006-127996, filed in the JPO on May 1, 2006 andthe entire contents of the Japanese patent application No. 2006-127996is incorporated herein by reference.

1. A transmission apparatus used in a mobile communication systemadopting a single carrier scheme in an uplink, comprising: multiplexingmeans configured to multiplex a pilot channel, a control channel, and adata channel; and transmission means configured to transmit atransmission symbol including at least the pilot channel and the controlchannel using the uplink, wherein the pilot channel includes a firstpilot channel used for a reception apparatus to measure channel state ofthe uplink and a second pilot channel for compensating for a channeltransmitted by the uplink, the data channel is transmitted using one ormore resource blocks, the first pilot channel is transmitted using afrequency band over a plurality of resource blocks, the second pilotchannel is transmitted by a resource block assigned to the transmissionapparatus, and control channels of the transmission apparatus and anapparatus other than the transmission apparatus are orthogonalized witheach other by a frequency division multiplexing (FDM) scheme.
 2. Thetransmission apparatus as claimed in claim 1, wherein control channelsof the transmission apparatus and the apparatus other than thetransmission apparatus are orthogonalized with each other by adistributed FDM scheme.
 3. The transmission apparatus as claimed inclaim 1, wherein the control channel of the transmission apparatus istransmitted using a resource block assigned for data channel of thetransmission apparatus.
 4. The transmission apparatus as claimed inclaim 1, wherein the control channel of the transmission apparatus istransmitted using a wide band equal to or greater than a resource blockassigned for a data channel of the transmission apparatus.
 5. Thetransmission apparatus as claimed in claim 1, wherein the controlchannel of the transmission apparatus is transmitted using a frequencyband of one or several number of resource blocks
 6. The transmissionapparatus as claimed in claim 1, wherein data channels of thetransmission apparatus and the apparatus other than the transmissionapparatus are orthogonalized with each other by the frequency divisionmultiplexing (FDM) scheme, and pilot channels of the transmissionapparatus and the apparatus other than the transmission apparatus areorthogonalized with each other by the code division multiplexing (CDM)scheme.
 7. A reception apparatus used in a mobile communication systemadopting a single carrier scheme in an uplink, comprising: receptionmeans configured to receive a transmission symbol including a pilotchannel, a control channel and a data channel using the uplink; andseparation means configured to separate the pilot channel, the controlchannel and the data channel from the reception symbol, wherein thepilot channel includes a first pilot channel used for the receptionapparatus to measure channel state of the uplink and a second pilotchannel for compensating for a channel transmitted by the uplink, thedata channel is received using one or more resource blocks, the firstpilot channel is received using a frequency band over a plurality ofresource blocks, the second pilot channel is received by a resourceblock assigned to each transmission apparatus, and control channels ofthe transmission apparatus and the apparatus other than the transmissionapparatus are orthogonalized with each other by a frequency divisionmultiplexing (FDM) scheme.